Alpine Redspot Dragonfly Indicative Distribution in NSW

The Alpine Redspot Dragonfly (Austropetalia tonyana) is a\r\nmoderate-sized dragonfly. The larvae grow to 32-35mm long and\r\nadults grow to 70-80mm long. It is a habitat specialist, occurring only\r\nwithin very specific geographic locations. It is naturally rare, with few\r\nrecordings of the species in New South Wales since the 1950s. In\r\nNSW, the Alpine Redspot Dragonfly is restricted to mountainous\r\nregions below 35°S that reach above 600 – 1,800 metres above\r\nsea level. Individuals have extremely specific habitat requirements in\r\nthat they only occur amongst rocks, logs and moss within the splash\r\nzone of waterfalls or in the nearby stream edge.\r\nThey are an endangered species -\r\nhttps://www.dpi.nsw.gov.au/fishing/speciesprotection/conservation/what-current/vulnerable-species/alpineredspot-dragonfly. \r\n\r\nThe methods used to create the predicted current\r\ndistribution of Alpine Redspot Dragonfly are described fully in: NSW\r\nDepartment of Primary Industries (2015), NSW Fish Community\r\nStatus 2015 – Final Report.\r\n\r\nAll available records of the species were collated and assessed for\r\naccuracy. For current distribution, only records after 1 January 1994\r\nwere used. Within the framework of the Australian Hydrological\r\nGeospatial Fabric V2 surface hydrology network, the records were\r\nassociated with attributes from the National Environmental Stream\r\nAttributes Database and River Styles® geomorphology. The\r\nAustralian Hydrological Geospatial Fabric V2 surface hydrology network (Geofabric) is a fully connected and directed stream network\r\nbased a 9 second DEM. It allocates a unique stream segment\r\nnumber to each river reach in Australia. The Environmental\r\nAttributes Database is a set of lookup tables supplying attributes\r\ndescribing the natural and anthropogenic characteristics of the\r\nstream and catchment environment that was developed by the\r\nAustralian National University (ANU) in 2011 and updated in 2012.\r\nThe data is supplied as part of the supplementary Geofabric\r\nproducts which is associated with the 9 second DEM derived\r\nstreams and the National Catchment Boundaries based on 250k\r\nscale stream network. 30 Stream variables were assessed for the\r\nmodelling.\r\n\r\nRiver Styles® provides a high resolution categorical classification of\r\nriver character within a nested hierarchy of criteria based on valley\r\nsetting, channel planform, geomorphic units, and bed material. The\r\nNSW Office of Water compiled a spatial dataset of River Styles®\r\nclassifications for a large number of the waterways of NSW. From 65\r\nRiver Style® categories we generated two new fields representing\r\nPlanform (34 categories) and Substratum (8 categories) for each\r\nstream segment. River Style® planform and substratum categories\r\nwere then assigned to each Geofabric segment.\r\n\r\nMaxEnt 3.3.3 is a widely used species distribution modelling program\r\nthat utilises presence records to generate probabilities of occurrence\r\nbased on a suite of environmental variables quantified across the\r\narea of interest. It was used to model the current geographic\r\ndistribution of each listed threatened freshwater aquatic species or\r\npopulation. We utilised logistic output to plot the predicted\r\ndistribution of each species. This output equates to a probability that\r\nthe species will be observed in each river reach, given the\r\nenvironmental conditions that exist there relative to the\r\nenvironmental conditions where the species is known to occur. For\r\nthis mapping, above 33% probability was considered predicted\r\npresence. In addition, predicted separate populations were\r\nconnected by manual interpretation. The predicted values for each\r\nriver reach were converted from the Geofabric framework to the\r\nhigher resolution 2013 NSW Strahler Stream Order Hydroline.